This proposal requests support for the acquisition of an ion trap-Fourier transform ion cyclotron resonance hybrid mass spectrometer. This new instrumentation is intended for the identification and quantitation of proteins from protein complexes, whole proteomes and single cells. This instrument is arguably at the forefront of mass spectrometry instrumentation, and represents a new platform for undertaking sophisticated proteomics-related studies. Proposed use of this instrumentation will support and enhance existing NIH-funded projects and provide avenues of research support that can lead to new funding for future projects. Four NIH-supported users of this equipment will form the core research team and the value added to their research activities by this instrumentation is discussed. All of these individuals currently interact with the University of Cincinnati Mass Spectrometry (UC MS) Facility, and the identified projects are untenable or pain-staking using the equipment already in place in the UC MS Facility. Their research interests, in some form or another, cover a wide spectrum of proteomics-related investigations. Examples include the effects of environmental agents such as estrogens, metals and PAH's on proteomes; examining the underlying biochemistry associated with microorganisms as they relate to biofilm production; and understanding the lamellar body proteome. All of the investigators participating in this instrument request have vigorous and well-funded research programs. In addition, a number of other investigator's NIH-funded research would benefit from this instrument acquisition. The PI, who has been active in the field of mass spectrometry for nearly 15 years, will be responsible for the managerial oversight of the requested instrumentation. He will report to an internal advisory board composed of scientists from various UC campuses and affiliates. The internal advisory board will establish scheduling priorities, work with the PI and accounting personnel to establish cost-recovery rates, and will serve as a resource for projecting future use of the requested equipment. The equipment will be housed in the University of Cincinnati Mass Spectrometry Facility. This 3,500 sq. ft. facility was renovated in 2001 and is equipped with the ancillary instrumentation required for proteomics. The instrumentation will be operated and maintained by two Ph.D.-level facility staff scientists, with one of these scientists having prior experience in both FTMS and proteomics being designated as the primary operator. These staff scientists are supported by B.S.-level staff technicians to ensure that the services are provided in a timely manner.